A program of research is outlined which will develop the observation that primaquine, an 8-aminoquinoline antiprotozoal agent, has potential for chemotherapy of Pneumocystis carinii infections. Modern drug design strategies, including computer-aided molecular modeling techniques, will be utilized to define the optimum 8-aminoquinolines structures for evaluation as pre-clinical candidates of P. carinii infections. Quinoline ring substituted analogs as well as 8-aminoalkyl side chain analogs will be prepared and evaluated. Structure-activity-relationship analysis will be performed and those 8-aminoquinolines predicted to possess structure for enhanced chemotherapy potential will be identified, prepared and evaluated. Pharmacokinetic parameters will be considered an important contributor to optimum characters for chemotherapy potential. This process will be repeated, if necessary, to define more optimal drug candidates from this class of agents. The candidates with highest potential for development will be selected and analytical methodology developed to monitor the candidate drugs and their expected metabolites in body fluids and tissues.